The Atlas of Global Conservation

Changes, Challenges, and Opportunities to Make a Difference

Jonathan M. Hoekstra, Jennifer L. Molnar, Michael Jennings, Carmen Revenga, Mark D. Spalding, Timothy M. Boucher, James C. Robertson, and

University of California Press Berkeley los Angeles london Thomas J. Heibel, with Katherine Ellison the nature conServancy Edited by Jennifer L. Molnar Contents

To future generations, and the planet they will inherit, Acknowledgments x

and in recognition of the generous support and vision of FOREWORD • A NEW VIEW OF OUR HOME xii Mark Tercek, The Nature Conservancy Bill Barclay and Ofelia Miramontes FOREWORD • CONSERVATION CONNECTIONS xiv paul R. Ehrlich, Stanford University

1. introduction 1

why ECOREGIONS? 6 Citation: Hoekstra, J. M., J. L. Molnar, M. Jennings, C. Revenga, M. D. Spalding, T. M. Boucher, J. C. Robertson, Taylor Ricketts, World Wildlife Fund T. J. Heibel, with K. Ellison. 2010. The Atlas of Global Conservation: Changes, Challenges, and Opportunities to Make a Difference. Ed. J. L. Molnar. Berkeley: University of California Press. Terrestrial Ecoregions, Realms, and Biomes 8

Freshwater Ecoregions and Basins 10 University of California Press, one of the most distinguished university presses in the United States, enriches lives around the world by advancing scholarship in the humanities, social sciences, and natural sciences. Its activities are Marine Ecoregions, Provinces, and Realms 12 supported by the UC Press Foundation and by philanthropic contributions from individuals and institutions. For more information, visit www.ucpress.edu. The Stories That Maps Tell 14 Jon Christensen, Stanford University University of California Press Berkeley and Los Angeles, California 2. hABitats 19 University of California Press, Ltd. London, England Forests and Woodlands: Giving Trees 22

Grasslands: Where the Buffalo Roamed 24 The mission of The Nature Conservancy is to preserve the plants, animals and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive. Deserts and Aridlands: Hardy Life under Harsh Conditions 26

© 2010 by the Regents of the University of California Rivers and Wetlands: The Planet’s Lifeblood 28

Library of Congress Cataloging-in-Publication Data Lakes: Fragile Pools of Life 30

Caves and Karst: Troves of Subterranean Species 32 The atlas of global conservation : changes, challenges and opportunities to make a difference / Jonathan M. Hoekstra [et al.] ; edited by Jennifer L. Molnar. hopE IN HABITATS 34 p. cm. Steven J. McCormick, Gordon and Betty Moore Foundation Includes bibliographical references and index. isbn 978-0-520-26256-0 (cloth : alk. paper) Coasts and Shelves: The Sea’s Sunlit Margins 36 1. Conservation of natural resources. 2. Environmental protection. 3. Globalization. I. Hoekstra, Jonathan M. 38 II. Molnar, Jennifer L. Coral Reefs: Crown Jewels of the Ocean S936.A75 2010 Mangrove Forests: Bridging Land and Sea 40 333.95'16--dc22 2009023617 Seagrass Beds: Marine Meadows 42 Project Management: Michael Bass Associates Cartography: Paula Robbins, XNR Productions Salt Marshes: Living Filters along Our Coasts 44 Design and Composition: Nicole Hayward Design High Seas and Deep Oceans: Earth’s Uncharted “Inner Space” 46 Text: Adobe Garamond Pro Display: Berthold Akzidenz Grotesk Prepress, Printing, and Binding: FourColour Imports, Ltd. 49 Title page photo: Ami Vitale 3. Species Plants: A Vital Variety 52 Manufactured in China Freshwater Fish: A Diverse Cast 54 18 17 16 15 14 13 12 11 10 10 9 8 7 6 5 4 3 2 1 Amphibians: Fragile Markers of the Planet’s Health 56

Reptiles: Prehistoric Survivors 58 This book has been printed on FSC Paper to be environmentally conscientious. The paper used in this publication meets the minimum requirements of ansi/niso z39.48-1992 (r 1997) (Permanence of Paper). ∞

nature.org/atlas Jennifer Molnar Jennifer MIGRATIONS 60 Dams and Reservoirs: Clogging Earth’s Arteries 124 Martin Wikelski, Max Planck Institute for Ornithology and Konstaz University, and 126 David S. Wilcove, Princeton University Sediment Flow: Starving Some Habitats, Smothering Others

Melting Ice and Rising Seas: Squeezing the Coasts 128 Birds: Everyday, Everywhere Wildlife 64

Disappearing Glaciers: Ice Storage on a Slippery Slope 130 Mammals: Shared Destiny with Our Closest Kin 66

NATURE CONSERVATION AND CLIMATE CHANGE 132 Endemic Species: In the Narrowest Niches 68 Jonathan M. Hoekstra, The Nature Conservancy Evolutionary Distinction: Branches on the Tree of Life 70 Terrestrial Invaders: Unwelcome Guests 134 PROMOTING LIVELIHOODS, SAVING NATURE 72 136 Greg Mock, former editor, World Resources Report Freshwater Invaders: Good Intentions with Costly Consequences

Marine Invaders: Stowaways Attacking Our Coasts 138

4. A World of Change 75 Terrestrial Animals at Risk: More in Jeopardy Each Year 140

Human Population: Outnumbering Nature 78 Freshwater Animals at Risk: Are Their Futures Drying Up? 142

Consuming Nature: Running Out of Planet? 80 Marine Animals at Risk: Sea Life Unraveling 144

Climate Change: The Planetary Emergency 82

147 uLTIMATE AGENTS OF GLOBAL CHANGE 84 5. Taking Action

Joel E. Cohen, Rockefeller and Columbia Universities Protected Areas on Land: Triumph for Nature 150

Habitat Loss on Land: Going, Going,… 88 Protecting Rivers, Lakes, and Wetlands: Thinking beyond Park Boundaries 152

Coastal Development: Reshaping the Seashore 90 Marine Protected Areas: Oases for Fish and People 154

Bottom Trawling and Dredging: Scouring the Seafloor 92 Protecting Nature’s Services: Dividends from the Wealth of Nature 156

Landscape Fragmentation: Going to Pieces 94 CONVERGENT CONSERVATION 158 Scott A. Morrison, The Nature Conservancy Thwarted Fish Runs: Up against a Wall 96

International Cooperation: Saving the Whales—and More 160 GLOBAL CONTAMINATION OF THE BIOSPHERE 98

John Peterson Myers, Environmental Health Sciences Greening the Marketplace: Certifiably Profitable 162

Freshwater Pollution: Clear but Hazardous 102 Collaborative Solutions: Problem-Solving Partnerships 164

Nitrogen Pollution: Too Much of a Good Thing 104 CONSERVATION ON OUR WATCH 166 Gretchen C. Daily, Marilyn Cornelius, and Charles J. Katz, Jr., Stanford University, and Ruin of the Reefs: Fading Jewels, Lost Wealth 106 Brian Shillinglaw, New Forests, Inc. Into the Wild: The Cost of Expanding Human Access 108 Rule of Law: Protecting the Commons 168 POVERTY AND nature’s SERVICES 110 170 M. Sanjayan, The Nature Conservancy Individual Action: Parting the Waters

Restoring Nature: Mending the Web of Life 172 Forest Clearing: Uprooting Nature 112

Water Stress: Overused and Undermanaged 114 6. Conclusion Our future, our choices 175 Overfishing:E mptying the Oceans 116

Wildlife Trade: Sold into Extinction 118 Appendix A: Ecoregions Index Maps 180 FUTURE OF FISHERIES 120 Jackie Alder, United Nations Environment Programme, and Appendix B: Technical Notes and References 200 Daniel Pauly, University of British Columbia index 229 Fire: Healthy Doses of Destruction 122 ABout the authors 234 2 Habitats

climate and currents. But the pace of human-driven changes in land use, water management, and ocean exploitation is For cheetahs, it is African savannas like the Serengeti. so great that there is a mounting risk For heelsplitter mussels, it is the muddy side channels of the that habitats and the species that depend Mississippi River. For the bizarre parasite Symbion pandora, on them may not be able to adjust quickly enough. it is the lips of Norwegian lobsters. This section of the atlas explores the global variety and current distribution Habitats are homes where species find the frigid and dark winters to revel in the of major kinds of habitat. Each page their niches. They can be placid lakes, midnight sun of arctic summer. In between highlights the uniqueness of these habi- snowy mountaintops, arid deserts, or deep these extremes, different combinations tats, the benefits they provide, the ocean trenches—anywhere on Earth of temperature and precipitation sustain dangers faced from human development, where species can find food, shelter, and grasslands, evergreen and deciduous for- and some ways that people can act to opportunities to reproduce. ests, and deserts. protect them. As a global species, humans depend Lake and river habitats are molded by on many different habitats far beyond the topography, geology, and climate, and Shaped by, and shaping, topography. Lake and river habitats are molded by topography, towns and cities where most of us spend they in turn can shape their environment. geology, and climate. Mountains are pocked with cold, glacial lakes and cut by fast, cascading our lives. We rely on the oceans for fish, Steep mountains are pocked with cold, streams. Lowland plains let rivers meander and fill shallow lakes and wetlands. grasslands for farmland and pastures, and glacial lakes and cut by fast, cascading lakes and rivers for water. Forests provide streams that provide homes for aquatic wood and other natural resources, and insects and trout. In lowlands, wide plains

they also help moderate changes in cli- let rivers meander and fill shallow lakes mate. Even if we rarely visit these habitats and wetlands that provide habitat for in person, we cannot live without them. larger fish and other species adapted to Some habitats, like coral reefs and slower waters. grasslands, are named after the domi- in the sea, habitats are shaped by cur- nant species found there, but all habitats— rents and temperature, and change with

and the vast variety of lives that they water depth. Along the coasts, bays and ublishing Group Ltd, 1984, 1993, 2005. sustain—are ultimately shaped by the estuaries are carved by waves, rivers,

physical environment. tides, and currents. Coral reefs and kelp © O ctopus P on land, climate gradients create dif- forests grow in sunlit shallow waters. As Source: Modified from The Gaia Atlas of P lanet Management Source:The Gaia Modified from ferent habitats from warm, wet tropical the water deepens and darkens offshore, forests with their mind-boggling diversity scallops and cod make their homes across of trees, orchids, birds, and insects to the continental shelf, while myriad strange cold, dry tundra where only the hardiest life-forms live in the ocean’s depths. heath plants, grouse, and caribou wait out in an ever-changing world, the distri- Varied with ocean depth. Marine habitats change with water depth, temperature, and currents. Coral reefs grow in sunlit shallow waters, Defined by climate. Habitats on land are shaped by the combination of bution of habitats can change with the while deeper, darker waters are home to varied species, from tuna temperature and precipitation that they experience. Warm, wet conditions plying remote oceans to luminescent fish living at extreme depths. support tropical rain forests, while cold, dry conditions support tundra.

20 Habitats 21 ent Mason K Forests and woodlands Giving Trees Sergio pucci/TnC

Natural complexities. wild forests (above) have complex structures, providing valuable habitat unmatched by plantations of trees (left) grown and harvested as a crop. Scott warren

data sources: Based on JrC 2003; CiESin et al. 2004. Majestic remnants. Large areas of intact forests now cover 10 FORESTS. Forests cover one-third of Earth’s land surface, with the largest remaining intact percent of Earth’s land surface, forests in the boreal regions of Asia, Europe, and north America, and the tropical Amazon and but they once spread over almost Congo basins.

Stephen Alvarez half of it.

FROM THE AMAzON JuNGLES to California’s dioxide, a leading greenhouse gas. They also Nearly 1,500 species of amphibians, birds, supercontinent that contained most of Earth’s which resemble forests yet do not provide instance, more forests are being managed oak groves, forests and woodlands are always help filter rain and melting snow entering mammals, and reptiles have been found land mass millions of years ago. Many types the same range of benefits or support as to store carbon. One of these is the Noel much more than collections of trees. Rather, streams, and offer shade that keeps the water in the southwestern Amazon rain forest— of trees can live for centuries, creating old- many species. The modern rate of loss is Kempff Mercado National Park in Bolivia, they are communities of interdependent cool for fish and frogs. Natural forests addi- about five times the number of those species growth forest habitats essential for the sur- accelerating, as is the degradation of what an area twice the size of New York’s Long plants, animals, fungi, and bacteria, which, tionally provide millions of sustainable jobs, documented in forests in the eastern United vival of many animal and plant species that remains, due to mining, logging, road build- Island, which is being managed with the together, support human survival as well. especially in the developing world where States. Elsewhere, forests harbor remnants of have adapted there over time, such as the ing, and clearing for cropland. goal of preventing the release of 5.8 million Woodlands differ from forests only in that many rural people still live off the land, ancient history. China’s temperate broadleaf great apes of Indonesia and marbled murre- As people become more aware of the con- tons of carbon to the atmosphere while con- they have more space between the trees, whether by tapping latex from wild rubber forests include plants closely related to those lets, seabirds that nest only in ancient forests tributions of intact forests—gifts becoming serving habitat and preserving traditional allowing a more open canopy. trees; gathering medicines, food, spices, and in the southeastern United States, echoing a along the northwest coast of North America. ever more conspicuous in their absence— forest jobs. Forests and woodlands produce much fuelwood; or, increasingly, working as stew- time before the continents drifted apart. The About 42 percent of Earth’s original for- increasing efforts are being made to preserve of the oxygen that people breathe and help ards or guides in protected wild places. evergreen “monkey puzzle” forests of South ests have been lost worldwide since the early what is left. With growing appreciation of stabilize the climate by absorbing carbon Forests—especially tropical forests—are America evolved in Gondwana—the 1700s—converted to human settlements forests’ contributions to climate stability, for some of the most diverse habitats on Earth. and agriculture as well as timber plantations,

22 habitats habitats 23 Grasslands Where the Buffalo Roamed

Drama on the plains. herds, like these wildebeests in the African savanna, migrate great distances across grasslands. Anup Shah/npl/Minden pictures

Life-sustaining fire. Fire is a recur- ring event in most grasslands, main- taining habitats that many grassland plants and animals depend on. harold E. Malde

Source: Based on hijmans et al. 2005.

data sources: Based on JrC 2003; CiESin et al. 2004.

GRASSLANDS. Many grasslands have been plowed under or converted to pasture for Not too wet or too dry. livestock, yet vast intact grasslands still remain in eastern Africa, central Asia, and northern Grasslands occur where it South America. is too dry to support forests yet too wet for deserts.

GRASSLANDS THROuGHOuT HISTORy have over land now covered with farms, cities, Many different animals have evolved to herbivore and plant. Grassland flora is spe- overgrazed and overfarmed. A more indirect fifteen years, conservationists have shown been open-air theaters of violent drama, and towns. make the most of life in these wide open cialized for survival, whether with long roots danger is that increased human settlements that managing grazing and fires can help re- as migrating, meat-eating predators have Grasslands occur in climates too dry spaces. Creatures native to grasslands tend that can reach a deep water table, thick bark have led to suppression of the fires on which store native communities of grassland plants stalked their migrating, grass-eating prey. to sustain forests but too wet for deserts. to have long legs or large wings, which help to resist the frequent fires, or thorns to ward some grasses rely to release seeds from their and even support the reintroduction of large On the hot, rolling African savannas— They are found on every continent except them travel great distances. Grasslands simi- off hungry animals. tough husks. By the early twenty-first cen- mammals, such as the American bison. grasslands dotted by acacia trees—lions Antarctica. In the heart of South America, larly have played a role in human evolution: Yet despite their adaptive arsenal, grass- tury, up to one-half of the world’s original In Mongolia, private and government and hyenas today still chase herds of wilde- savannas occupy an area about one-fourth transitioning from a four-footed life in the lands and the life they support are succumb- grasslands had vanished, with most rem- groups have helped conserve twenty-eight beest, zebras, and antelopes. Such scenes of the size of Canada, offering homes for jungles, humans learned to walk and run ing rapidly to human development. The nants sliced up by roads. thousand square kilometers of the world’s pursuit and flight were once also common the large capybara rodent and marsh deer. and scan the horizon for prey. features that make them most hospitable to The ancient dramas of grassland life might largest intact temperate grassland, an area on the prairies of North America, where On the remote high plains of the Tibetan The grassland drama of carnivore and her- life—their flatness and fertility—put them seem to be in their final season, were it not threatened by nearby development of roads, wolves and grizzlies chased bison and elk Plateau, grasslands cover an area almost as bivore is mirrored in the struggles between most at risk. Ideally suited for ranching and for new conservation efforts by scientists, mines, and oilfields yet still home to migrat- large as the U.S. state of Montana. agriculture, in many regions they have been activists, and governments. Over the past ing nomads with their yaks.

24 habitats habitats 25 deserts and Aridlands Hardy Life under Harsh Conditions henner Frankenfeld/redux pictures

Man-made deserts. while natural deserts can be vibrant and full of life, vast regions are being converted from dry grasslands to barren deserts. This human-induced desertification—the loss of vegetation and the degradation and drying of the soil—is a product of deforesta- tion, overgrazing, and wasteful irrigation practices, aggravated by climate change. desertification threatens the survival of more than 250 million people, like this Tanzanian herder, who depend on dry- lands for crops and grazing of livestock.

Quenched by fog and dew. in the namib desert, Welwitschia mirabilis, also known as “tumboa,” absorbs moisture through its leaves. The tumboa data sources: Based on JrC 2003; CiESin et al. 2004; hijmans et al. 2005; kottek et al. 2006. grows very slowly and can live for over a DESERTS AND ARIDLANDS. The world’s major deserts include the Sahara, Arabian, Gobi, thousand years. and Great Basin in western north America. Michael & patricia Fogden/Minden pictures & patricia Michael

LOW, uNPREDICTABLE RAINFALL, high evapo- lichens called cryptogams. Combined with thick, bright white fur that reflects the sun’s Apparently timeless and unchanging, Throughout the ages, travelers in search and cheatgrass, for example, have taken ration rates, and, in most cases, an abun- bacteria and fungi, cryptogams form a living rays in summer but absorbs the warmth in deserts are increasingly being transformed of solitude and inspiration have also been over and devastated huge areas of North dance of paradoxes are common denomina- crust that holds scarce water in place and winter. Gila monsters store water in their by human activities. Eight percent of the drawn to desert wilderness. These incursions America’s Great Basin Desert. However, in tors of the world’s aridlands, which cover keeps soil from blowing away. But crypto- tails. The Namibian tumboa plant absorbs world’s human population live in deserts have damaged the fragile environments. at least one area, Hells Canyon of Idaho, about 40 percent of the world’s total land gamic crusts can crumble under the weight fog and dew through its leaves. Australia’s and the aridlands on their margins, eking Cryptogamic crusts and other fragile flora conservation groups and state agencies have surface. While deserts seem empty, they are of just a footstep, making deserts some of Eyrean grasswren, a small bird, has such ef- out incomes from livestock, mining, and have been destroyed by off-road vehicles and been tracking the plants’ progress by flying usually full of life. Earth’s most fragile landscapes. ficient kidneys that it does not need to drink minimal farming. Desert and aridland habi- other means. over the area in small planes and helicopters, Look closer at the seemingly bare land- Resident animals are characterized by water—it gets all the moisture it needs from tats throughout the world have also been Many opportunities do remain to protect returning by land to remove the invasives, scapes beyond the scraggly foliage of the extraordinary adaptations that allow them the seeds and insects it eats. Plants have lost to irrigated farming and urbanization, desert habitats with improved fire manage- whether with fire or grazing animals, or by world’s driest places. It turns out many are to survive in these all but inhospitable ter- similarly evolved to fit their habitat: many while the introduction of invasive plant spe- ment, careful grazing practices, and control pulling the plants out by hand. not really bare but are covered by algae and rains. The endangered Arabian oryx, which of them grow, flower, make seeds, and die in cies and the suppression of fires have trans- of invasive plants. Invasive yellow star thistle resembles a long-horned antelope, has just the few days of rain during the year. formed immense expanses of these habitats.

26 habitats habitats 27 rivers and wetlands The Planet’s Lifeblood Brian richter/TnC

Life-giving floods. The annual rainy season brings essential water and nutrients to the okavango delta. hundreds of species, from Cape buffaloes and lechwe antelope to tiny invertebrates, could not survive without this seasonal flooding. richard du Toit/Minden pictures du Toit/Minden richard

The Mighty Mekong River. The Mekong runs 4,800 kilometers from the glaciers of the Tibetan plateau through data sources: Based on ErSi 1992, 2005; Lehner and döll 2004. six countries before entering the South China Sea. it is home to the Mekong giant catfish, which can grow up to three meters in length and weigh three hundred kilograms and RIvERS AND WETLANDS. Climate, topography, and geological events such as the is now close to extinction because of overfishing and habitat loss. The advancing and retreating of glaciers have shaped the distribution of rivers and wetlands lower Mekong Basin waters contain the world’s most productive inland throughout the world.

Zeb hogan fisheries, providing protein and incomes to forty million rural dwellers.

RIvERS HAvE ALWAyS BEEN POTENT sym- deep, slow-moving waters of main river Floodplains and wetlands typically harbor Okavango River flows down from the high- Indeed, river and wetland fisheries often include draining wetlands, withdrawing bols of time and change, shifting shape as channels. Smaller species, such as Australia’s the greatest number of species. Renewed lands of Angola. The Okavango offers habi- provide the only source of animal protein for too much water for agriculture, polluting they travel from the mountains to the sea. climbing galaxids, which got their name for each year with river-borne nutrients, these tat for a large array of plants and animals people in much of the developing world, par- rivers with fertilizer, dumping waste, over- Fast-flowing streams dominate their upper their ability to wriggle up waterfalls, inhabit habitats are sprawling nurseries for aquatic that would otherwise succumb to the desert ticularly the rural poor who turn to fishing harvesting fish, and introducing non-native reaches, growing larger and slower as they the shallower headwater streams. Other spe- plants, insects, worms, and other inverte- heat. It also provides food for more than a when they cannot find other jobs. In Laos, species. All these threats pose major chal- descend toward wetlands and the coast. cies, native to arid regions, have adapted to brates, which in turn attract large numbers hundred thousand indigenous people, and over 70 percent of farmers are also involved, lenges to conservationists, who nonetheless No two rivers are exactly alike. Climate, periods when rivers run dry or are reduced of fish, mammals, and birds to feed and spectacular views for visitors supporting at least part-time, in fishing activities to aug- are making progress. A case in point in the geology, the chemistry of the water, and the to a few standing pools until the next rainy breed. One of the world’s most magnifi- Botswana’s lucrative tourism industry. ment their family food supplies and incomes. United States is the Connecticut River and contours of the land all determine a river’s season. The Australian salamanderfish, for cent wetlands is Africa’s Okavango Delta Throughout the world, rivers and wetlands Over time, we have heavily altered wa- its tributaries, which are reviving today after characteristics and the varieties of life that example, clings to life during the annual dry in the margins of the Kalahari Desert, an play similarly vital roles in people’s lives, terways to fit our needs by building dams, forty years of efforts to protect land, restore it supports. As a rule, large fish such as the period by burrowing in the mud and cover- alluvial fan of fifteen thousand square kilo- providing shipping routes, hydropower, rec- levees, and canals. Other harmful practices, shoreline vegetation, improve sewage treat- Mekong giant catfish can be found in the ing itself with a thick layer of mucus. meters that floods every rainy season as the reation, jobs, and food and drinking water. which today are unfortunately widespread, ment, and manage fish and recreation.

28 habitats habitats 29 Lakes Fragile Pools of Life Broudy/donohue photography/Corbis

Saving Himalaya’s lakes. Lake Gokyo was one of the four glacial lakes protected by nepal in 2007 under the Convention on wetlands. This system of lakes near Mount Everest is a vital water source for local communities and is home to threatened species, including the reclusive snow leopard.

The unique freshwater seal of Baikal. The nerpa, found only in Lake Baikal, is the world’s only strictly freshwater seal. it can live over fifty years and stay underwater for up to forty- three minutes. konrad wothe/Minden pictures konrad

World’s largest lake. Lake Baikal holds one-fifth of the world’s data source: Based on Lehner and döll 2004. freshwater. More than 330 streams flow into LAKES AND MAN-MADE RESERvOIRS. Lakes are most prevalent in the northern the lake, but only the latitudes, where many were formed by glaciers of the last ice age. dam building has produced Angara river flows out more man-made reservoirs in developed countries, although less developed nations are toward the sea. quickly catching up. konstantin Mikhailov/ konstantin natura/MindenFoto pictures

FROM THE vAST Great Lakes of North colonize these new environments and gradu- else on Earth. In comparison with Lake water into standing water, with the result love our lakes to death. The most prevalent Some of these threats can be abated America to tiny Gokyo Lake, nestled high ally adapt to their conditions. Baikal, most other lakes in the world are that native river fauna often cannot adapt threats to lakes today are pollution from through sound management and conserva- in the Himalayas, lakes in their many differ- Lake Baikal in southern Siberia is the relatively young, having formed within the and survive. Many reservoirs are also inten- sewage, industrial effluents, and fertilizers tion. Back in the 1960s, Lake Washington in ent forms sustain a wide variety of natural world’s oldest and deepest freshwater lake. last ten to twenty thousand years. Younger tionally stocked with non-native fish species, running off farmland. Nutrients in sewage the U.S. Pacific Northwest was dominated life. Much like islands, they provide habitats Formed by a deep crack in Earth’s crust lakes generally have many fewer species, but such as trout or bass, which can end up and fertilizer end up feeding algae and plant by toxic algae and unfondly called “Lake in which freshwater plants and animals can more than twenty-five million years ago, these species continue evolving today. competing with native species. While there life that then rob the water of its oxygen Stinko” by locals, as a result of many years evolve in isolation. it holds nearly one-fifth of all the world’s Reservoirs look like lakes and are often are still many more lakes than reservoirs, as they die and decay. This process—called of dumping of raw sewage from Seattle Lakes are formed after glaciers, volcanoes, freshwater, roughly equal to the volume of mistaken for them. Yet they are different there are now reservoirs on nearly every river eutrophication—results in the suffocation of and surrounding areas. The lake has since or earthquakes leave craters that fill with wa- all the North American Great Lakes com- in important ways. Reservoirs are artificial system on Earth. fish and other species. Other pressures on recovered, however, as managers have built ter. Next, species from surrounding waters, bined. And just as outstanding as its size environments, formed by a dam that in- People use lakes and reservoirs in all sorts lakes include overharvesting of fish, the pro- sewage treatment plants, and is now a popu- as well as seeds carried by wind and wildlife, is the quantity and variety of plants and terrupts a river’s flow and floods the land of ways—they are fish tanks, sources of ir- liferation of invasive species, and the lower- lar place for recreation and home to nearly animals that it sustains: in all, 2,630 species, behind it. Reservoirs transform flowing river rigation water, and fields for Jet Skis. And ing of water levels from excessive water use. thirty species of fish. three-quarters of which are found nowhere as with other elements of nature, we often

30 habitats habitats 31 Caves and karst Troves of Subterranean Species

An underground blue world. The Quintana roo province in Mexico contains more than 685 kilometers of underground rivers, including the ox Bel Ha, the world’s longest surveyed underwater cave

henry watkins & henry watkins Aragon/reuters/Corbisyibran system.

Rare and out of sight. The endangered Benton Cave crayfish is found in just four sites within the ozark karst system of the u.S. state of Arkansas, with only forty individuals known to exist. Stephen Alvarez

Disappearing Stream Limestone

Interconnected landscapes. karst caves contain their data source: Based on williams and Ford 2006. Cave own ecosystems, and their freshwaters often nourish aboveground KARST TERRAIN. Many caves remain unexplored or even still undiscovered, but karst terrain—limestone or other soluble rock formations—illustrates where karst caves, and thusly Volcanic or rivers and streams. Sedimentary Rock cave species, are likely to exist.

HIDDEN AWAy BELOW OuR FEET, some of the The darkest reaches of this cavern- single location. The endangered Benton Scientists estimate that karst terrain occu- fertilizers, sensitive cave species suffer. The subterranean fish species quadrupled in world’s rarest and weirdest creatures dwell ous world are home to a class of specially Cave crayfish—a blind, transparent crusta- pies nearly 15 percent of Earth’s surface— blind Aigamas Cave catfish found only in comparison with findings from the preced- in underground caverns, tunnels, and caves. adapted creatures: troglobites, which, hav- cean that can live as long as a human—is a vast area that nonetheless remains largely the Aigamas Cave in Namibia, has arrived ing sixty years. And recently, an ad hoc These mysterious abodes have been created ing evolved without light, rely on highly found only in a handful of sites within the unexplored, with many still-unknown spe- at the brink of extinction as karst water sup- coalition of conservationists, landowners, in various ways: from cooled tubes of lava, developed other senses, including smell, U.S. state of Arkansas’s Ozarks karst system. cies. Once documented, these permanent plies have dwindled. Similarly, water pollu- and public officials has worked to protect the force of waves battering rocky coasts, taste, and vibration detection. Usually these Other, more common species come and go cave dwellers are ideal indicators of the tion and diversion to reservoirs has damaged sensitive habitats in the Ozark karst system or, most often, from the formation of karst. species have little or no pigmentation and as they please. Bats may roost within caves, health of a given environment, since they Central Europe’s vast Dinaric karst, threat- by improving groundwater quality, regulat- Karst caves form when water percolates either rudimentary eyes or no eyes at all. leaving them to feed and, in the process, are extraordinarily sensitive to changes in ening such unique species as the “human ing disposal of hazardous materials, con- through soluble portions of Earth’s crust, Troglobites also tend to have remarkably routinely importing nutrients back home. the quantity and quality of the water seep- fish” salamander. ducting volunteer cleanups and restricting dissolving rocks such as limestone and do- slow metabolisms, allowing them to thrive Other animals, such as frogs and bobcats, ing in from above. Unfortunately, many of Yet together with the new threats to access to important cave sites. Other coun- lomite. Small spaces over time become vast in environments with little food to spare. spend most of their time aboveground them are not faring well. cave species has come new interest in under- tries such as Brazil, Australia, Mexico, and subterranean tunnels and grottoes, often Cave habitats are usually so isolated from but use caves for water and shelter during As increasing human populations above- standing and preserving them. Between 1980 Croatia have recently taken measures traversed by streams, rivers, and lakes. one another that they are high in endemism, droughts or cold spells. ground use water for irrigation and drink- and 2005, the rate of discovery of new to protect cave habitats as well. with many troglobite species unique to a ing, and pollute water with pesticides and

32 habitats habitats 33 Hope in Habitats

Steven J. McCormick priorities based on considerations such as threat, and the extent to which habitat types are currently protected in different regions I first became enraptured with the natu- of the world. ral world in the late 1950s, playing with a band This atlas is a culmination of that com- of friends in the woods—or, should I say, “the mitment. And what a wonderful, insightful jungle.” For that was the name we gave to the resource it is! While no major habitat types mixed oak woodland (not a phrase that was are sufficiently conserved on a global scale, in the lexicon of eight-year-old boys) behind what this atlas reveals is that some are alarm- our neighborhood in Northern California. ingly overlooked. Temperate grasslands, for Many weekends we’d march off to the example, do not have the glamour or drama, jungle for a long day of climbing the burly, say, of an African savanna or the abundance gnarled limbs of coast live oaks and explor- of species of a so-called tropical rain for- ing the dark, spicy interiors of dense bay est hotspot, but as an element of biological forests. Those boyhood experiences, pursued diversity, these grasslands are no less signifi- solely for the sheer joy of unconstrained, un- cant. Yet less than 5 percent of the world’s structured adventure, profoundly influenced temperate grasslands are represented in pro- and shaped my growth to adulthood. tected areas, and most are heavily altered by We didn’t think of the jungle as a “habi- a long history of human agricultural use. tat type,” but we did appreciate the forest as Focus on habitats also requires us to more than just a bunch of trees. The creeks think in terms of what it will take to as- were full of “water skeeters” and other bugs; sure conservation of functioning natural salamanders were abundant in early spring; systems, and to go beyond the convention gopher snakes prowled the open areas; quail of thinking of protected areas as the only erupted from underbrush; deer were almost approach for conservation. At the enormous always browsing early in the morning. scale required to assure meaningful con- I can’t say that my experiences in the jungle servation, we’ll need to act with a commit- launched a career in conservation, but they ment to assuring legitimate human needs were certainly a powerful influence on my and desires. Those of us who’ve had the life. When I first started working for The luxury of coming to a conservation ethic in Nature Conservancy in 1977, I was convinced a prosperous nation must understand that that we should focus more on conserving “nat- the terminology we use—protect, preserve, ural communities” (a synonym for “habitat save, set aside—is taken as arrogant at best, types”) than on individual species, because— and confiscatory at worst, to those strug- C as I knew from my days in the jungle—not gling for survival. The term habitat should only was the whole system more than be appreciated for its imperative for human the sum of the parts, but the parts required well-being, not just for the preservation of the whole system (a pretty sophisticated the other species that reside there. After all, Mark Godfrey/T N ecological awareness for someone trained as we humans also live in virtually every habi- Mediterranean woodlands, California, United States a lawyer). tat on the planet. This realization suggests a When I became president of The Nature whole new precept: conservation of habitats Conservancy in 2001, I wanted to make for people; not protection of nature from this the guiding principle for the whole people. We also need to collaborate with It’s smaller and less exotic than I recall it. of hope for the future. This small but endur- organization. And, inasmuch as the mis- many partners to develop creative solutions. But the forest, redolent of bay and tanbark ing habitat, surrounded by development, sion of the Conservancy compels a global It is clear that no one approach or one group oak—what I now know is Mediterranean, a was alive with small children, doing exactly vision (“to preserve the … diversity of life can single-handedly reverse the current habitat type that has been heavily impacted what I did at their age. on Earth”—my emphasis), I was commit- extinction crisis, tackle climate change, or by people here and elsewhere around the ted to undertaking a global assessment of prevent ecosystem degradation. world—not only brought back powerful, steven j. mccormick is president of the all habitat types to determine conservation Last year I returned to live in Northern and immediate, memories of a wondrous gordon and betty moore foundation. California. The jungle is still there, intact. boyhood but also kindled a profound sense

34 habitats Habitats 35 Coasts and Shelves The Sea’s Sunlit Margins

data source: TnC 2007.

KELP FORESTS. Though not a dominant coastal feature in much of the world, kelp forests are abundant and diverse in the temperate waters of the northern pacific ocean.

data source: TnC 2007. Beyond the waves. The continental shelf uPWELLINGS. in many regions, currents bring cool, is home to plants, nutrient-rich waters from the deep sea onto the continental Above the tides. Intertidal. Salt marshes, invertebrates, and in shelf, feeding diverse forms of life. upwellings off peru and Though scoured by mangroves, and shellfish reefs some regions even Chile are the richest, supporting over 15 percent of the wind and doused by sea thrive in dynamic zones that underwater forests of world’s marine fish catch. spray, marine turtles are covered and uncovered by kelp that form three- and seabirds like the the tides. dimensional habitats. red-footed booby shown here find coastlines invit- ing places to rest, nest, and rear their young. Jennifer Molnar Jennifer Mark d. Spalding richard herrmann richard

WHEREvER LAND TILTS into the sea there is communities of life that vary according to cling to the rocks, competing for space kilometers from the coast, dominated by world’s oceans, kelp are most widespread providing homes to many species of fish a complex transition of worlds. First comes the nature of the seabed and the force of the where sunlight and oxygen are plentiful. sand and mud. Scientific convention holds in cooler, nutrient-rich waters, such as the and crustaceans. the intertidal zone, a place of constant mo- waves. Salt marshes and mangroves grow Sandy shores, by contrast, are not so densely that the continental shelf stops when it Pacific Ocean coast of Canada and the Marine life is most varied and abundant tion, swept by currents, waves, and tides, in fine silt or mud where waters are calm. populated but provide resting areas for tur- reaches a depth of about two hundred me- United States. There, rich kelp forests grow in coastal waters—and human activities yet sustaining myriad creatures and plants. Below these, mudflats often stretch out in tles and seals. Estuaries and deltas are more ters, after which there is often a steep drop up from the seafloor to heights of twenty such as fishing and boating are also most Below the tides’ play, shallow sunlit waters wide expanses, providing habitat for bacte- complex places, forming the nexus of land, to the inky depths of the deep sea, a place meters or more. intense here. In addition, human develop- teem with life. The seafloor slopes gently ria, algae, and burrowing animals such as freshwater wetlands, and the ocean. Here, still rarely visited and poorly understood. Living reefs are another common feature ment along the coasts has had a tremendous away from the land, and as the waters razor clams, which in turn attract masses of insect larvae and crustaceans scurry together, Areas reached by sunlight may be colonized of the continental shelf. Best known, and and mounting impact on adjacent waters. deepen, the flow of nutrients from land di- wading birds, foraging fish, and crabs. and schools of fish congregate to spawn, by plants, including seagrasses and algae, home to the greatest diversity of species, are In contrast to efforts on land, however, minishes, sunlight is filtered, and the seabed Different types of coastlines are home to leaving billions of eggs and fish larvae. Mud and by invertebrates such as worms, mol- the coral reefs found in tropical zones. But conservation efforts in coastal waters have becomes more sparsely populated. distinct assortments of life. Rocky shores crabs filter the sediment, while, in the trop- lusks, and starfish. Rocks rising from the other large reefs formed from the skeletons been much more limited, with fewer areas The intertidal zone is a strand of some- host a suite of flora and fauna that includes ics, large crocodiles hide in ambush. seabed support larger life-forms, including of animals and plants, including worms, protected and fewer regulations to prevent times-water, sometimes-land that harbors seaweeds (macroalgae), mollusks, anemones, The continental shelf is a shallow coastal corals, sponges, sea fans, and large seaweeds mollusks, and even a red-colored algae, pollution or over-exploitation. crustaceans, and tiny bryozoans, which region stretching as far as hundreds of known as kelp. Found throughout the called maerl, are found in cooler waters,

36 habitats habitats 37 Coral reefs CORAL REEFS. Coral reefs are Crown Jewels of the Ocean abundant throughout the indo-pacific ocean region, from East Africa and the red Sea to the central pacific ocean, Tiny builders, big results. Tiny where many of the islands are built coral animals form colonies that entirely by coral reefs. reefs are also provide shelter for fish and the abundant through the Caribbean. raw materials that have built great coral reefs and even islands, such as here in the Cook islands. Steve Allen/Getty images

Providing crucial resources. The rich resources of coral reefs are widely utilized, not only by birds, but by millions of fishers in over data source: Based on unEp-wCMC 2003.

one hundred countries. Mark d. Spalding

CORAL REEFS are undersea monuments, marine biologist identified 284 different fish People living on tropical islands depend change. Corals are highly sensitive to fluctua- built up over thousands of years by billions species during a single dive along the reefs of on the reefs for their diets and incomes. tions in sea temperature, and since the mid- of stony coral polyps. The polyps are tiny the Raja Ampat Islands, Indonesia. In sub- Inhabitants of tiny atolls, such as the 1990s, warm summers in the Caribbean, the creatures, each consisting of little more than sequent expeditions, scientists have tallied Maldives and Marshall Islands, actually live Western Indian Ocean, and the Great Barrier stinging tentacles, a mouth, and a stomach. a total of 1,149 different fish, 537 different on land made of coral and sand, piled up Reef have caused widespread coral death. They live in close-packed colonies, and as coral species, and more than 700 mollusks by storms, or sometimes uplifted by ancient Hope rests in a combination of science, they die, they leave behind limestone skele- from these islands, which lie in the Coral earthquakes. In many countries, reefs are a common sense, and concerted efforts. tons to which new polyps attach. Over time, Triangle, home to the richest variety of all lucrative tourist attraction, since visitors will Scientists have realized that small areas of the skeletons become reefs, which can ex- marine life. travel far to snorkel and scuba dive among reef often survive the more widespread coral tend for hundreds of kilometers, growing up Coral reef scientists recognize two major healthy, diverse coral gardens. Reefs also death that has occurred in recent warm sum- toward the surface of the sea. The still-living regions of coral reefs in the world. The vast reduce the impacts of waves, providing pro- mers, and that reef recovery more generally polyps are what give the reefs their jewel-like Indo-Pacific region, stretching from East tection from storms. is enhanced where reefs are free from other Data source: Based on Veron 2000. colors. The Great Barrier Reef, the larg- Africa and the Red Sea to the central Pacific Despite this immense value, many coral human impacts such as overfishing. Working est geological structure ever built by living Ocean, has the greatest extent of reefs and reefs are in decline. They are highly vulner- with expert knowledge of both scientists and STONy CORAL SPECIES. The Coral Triangle hosts things, stretches almost two thousand kilo- highest diversity of species. By contrast, able to overfishing; in parts of Southeast Asia, local fishers, conservationists have created the greatest diversity of coral species, in addition to other meters along the northern coast of Australia, the Atlantic coral reefs, most abundant they are being destroyed by fishers who use a plan for the communities around Kimbe types of life such as fish and mollusks. in comparison, the covering an area the size of Finland. around the Caribbean and the Bahamas explosives to guarantee a maximum catch. Bay, Papua New Guinea, to safeguard these Caribbean is much less diverse yet hosts species unique to Coral reefs have long been famous for the Archipelago, have lower diversity, but their Pollution and silt from inland agriculture resilient coral reefs and to foster rapid recov- its region. Stony corals are also found in regions—including diversity of life that they support, vying even corals and fish are unique to this region, and coastal development are also degrading ery from future impacts, using traditional the Mediterranean Sea and west Africa—where their with tropical rain forests in that regard. Yet having evolved in isolation for hundreds of the reefs. The greatest long-term threat may management approaches but ensuring that numbers are insufficient to build reefs. even reef experts were surprised after one thousands of years. be the warming of the oceans due to climate critical areas are safeguarded for the future.

38 habitats habitats 39 Mangrove Forests MANGROvE FORESTS. Mangrove Bridging Land and Sea forests today cover about 150,000 square kilometers. They are widespread in all tropical realms but are most common A tended forest provides. The along low-lying coastlines in areas with Matang forest of Malaysia is likely generous rainfall. the longest continuously har- vested tropical forest in the world. Beginning in 1902, Matang’s stew- ards have carefully tended the four hundred square kilometer forest and have been richly rewarded. Today, some 2,200 people are employed in timber extraction and processing, while the associated fishing indus- tries provide livelihoods for over

Courtesy of AsiaExplorers/www.asiaexplorers.com 10,000 people.

A rare sight. Found only on the island of Borneo, the proboscis monkey dines on mangrove leaves and unlike other monkeys it is an excellent swimmer.

data source: Based on Spalding et al. 1997. Thomas Marent/MindenThomas pictures

MANGROvES TREES inhabit a world midway of animals. Hordes of fiddler crabs march provide income as valuable exports. They and 2005, they lost thirty-five thousand between land and sea. They thrive in swamps, across the mud as the tide falls, the males are an important nursery for many coral square kilometers, almost one-fifth of their roots sometimes inundated by the rising waving a specialized giant pincer—attracting reef and seagrass fish. Even far offshore, spe- their total extent. This was mostly through tide. Scientists have catalogued some sixty- mates and deterring rivals. Mudskippers, an cies such as the prawns taken in northern overharvesting of wood or to make way for five species of these trees, all uniquely adapted amphibious fish, climb up tree roots to graze Australia’s massive prawn capture fishery rely aquaculture ponds, agricultural land, and to survive in the intertidal zone, sometimes on algae in the open air. Archerfish stay sub- on mangroves for part of their lives. urban or tourist resort development. And in salty water, always in waterlogged earth. merged but squirt jets of water from their In many parts of the world, mangrove now, as their gifts are being recognized, Mangroves’ most distinctive features are their mouths to dislodge insects from the leaves forests are living sea walls. They baffle waves, many mangrove forests are receiving in- strange, adaptive root structures, all exposed above. In the vast Sundarbans mangrove prevent erosion, and protect coastal settle- creasing levels of protection, while others data source: to air at least part of the day so as to sip pre- of Bangladesh and India, tigers stalk their ments from devastation by storms. News re- are being managed sustainably for forestry Based on Spalding et al. (forthcoming). cious oxygen from an otherwise anaerobic prey. Hippos rest in the mangroves of West ports in the wake of the 2004 Indian Ocean and fisheries. Countries such as Cuba, terrain. These include pneumatophores, root Africa, while the extraordinary, long-nosed tsunami said mangroves helped shield some Bangladesh, Vietnam, and the Philippines MANGROvE SPECIES. The vast majority of the world’s sixty five extensions growing upright from the mud; proboscis monkey, which feasts on man- villages from the worst ravages of that di- have each planted hundreds of square kilo- mangrove tree species are found in the Central indo-pacific, which “prop roots,” looping from branches and grove leaves, is found only on the island saster. Their complex roots and meandering meters of mangroves to replace lost forests is also a center of diversity for corals and seagrasses. Far fewer trunks; and “knee roots,” resembling strange of Borneo. channels also filter water and help consoli- and to safeguard coastlines and fish stocks. species are in the Atlantic and the Tropical Eastern pacific. knobby knees that poke up through the mud Mangroves also support millions of date the shore by capturing sediment carried from the web of roots below. people by providing timber, fuelwood, and by rivers or swept along the coast. In and among the great forests formed food. The mud crabs and oysters, prawns Mangrove forests are disappearing faster by these trees dwells an equally distinct mix and finfish nurtured among their roots add than any other forest type. Between 1980 protein to the diets of nearby villages and

40 habitats habitats 41 Seagrass Beds SEAGRASS HABITAT. Seagrasses are Marine Meadows most extensive in the tropics but also cover large areas in the northern Atlantic, Mediterranean Sea, and temperate In cold waters. unlike Australasia. Scientists estimate that these corals and mangroves, sea- meadows cover at least 177,000 square grasses grow in temperate kilometers of seafloor. and even polar waters. here a giant pacific octopus is foraging the waters off British Columbia, Canada. Fred Bavendam/MindenFred pictures

Gentle giant. The dugong is a marine mam- mal that feeds on seagrasses, here in Vanuatu, pacific ocean. Mike parry/Minden pictures

Protecting the young. Seagrasses can form dense beds over sands and silts and provide data sources: Based on unEp-wCMC 2005; Green and Short 2003. important shelter for juvenile fish. Mark d. Spalding

PICTuRE A MEADOW where turtles and mana- fields on land, they are fast growing and highly fisheries from undamaged seagrass areas in underwater meadows are being plowed un- tees graze. The ebb and flow of water ruffles productive, while the complex network of countries such as Belize and the Bahamas der by trawling and dredging. While there the foliage like a breeze, while millions of roots and leaves creates a three-dimensional are worth many millions of dollars in ex- are no accurate measures for the overall loss, crustaceans, mollusks, and starfish stand in habitat. Algae and small invertebrates settle ports every year. one conservative estimate suggested that for scurrying insects and rodents. and grow on the seagrasses themselves, ac- Seagrass beds also improve water quality, some twelve thousand square kilometers of This underwater field is made of sea- companied by hundreds of species of fish by filtering out nutrients and contaminants seagrasses vanished from the mid-1980s to grasses, the world’s only fully submerged and large invertebrates such as shrimps and and trapping sediments. The complex net- the mid-1990s. plants with roots in marine and tidal zones. crabs. A study of seagrass bed inhabitants in works formed by their roots help stabilize The extraordinary-looking giant dugong, Scientists to date have identified some just one bay in temperate Australia found 631 the seafloor and soften the impacts of waves, typically weighing in at one-quarter of a data sources: Based on sixty of these strange and highly specialized invertebrate species, while in the U.S. state preventing erosion not only underwater but metric ton, seems an unlikely savior for the unEp-wCMC 2005; Green and Short 2003. plants, originating from a variety of different of Florida 113 different kinds of algae were also on adjacent shores, and reducing prop- seagrasses, but in Had Chao Mai, Thailand, plant families. None are in fact true grasses, found growing on and among the plants. erty damage from storms. the appearance of these rare creatures led to SEAGRASS SPECIES. As with coral reefs and mangrove forests, but many have grasslike blades. Given suffi- Hidden just beyond our crowded shores, With all these benefits largely unknown a mass media campaign, with local conserva- the major center of seagrass diversity is in the Central indo-pacific cient bright sunlight and a soft bed for their seagrass beds are an often-undervalued part or ignored, seagrasses around the world are tion organizations persuading villagers to ocean. however, seagrasses have other centers of diversity in roots, they will spread over vast expanses of of nature. Yet they do much to support diminishing. Pollution has spurred increased stop using fishing methods that were damag- the warm temperate waters of southwestern Australia, and in the the shallow seafloor. other life, including humans. The great growth of algae and phytoplankton that ing the dugong’s seagrass food, and to use northwestern pacific ocean. At first glance, these uniform underwater range of biodiversity they sustain includes block vital sunlight from the seabed; coastal fish traps instead. Since then the seagrasses meadows might not seem capable of support- important fishery species, among them development has smothered wide areas with have expanded, and, to the delight of the ing rich and diverse species. Yet just like grassy crustaceans, mollusks, and fish such as snap- sand and rubble; and in many areas, these fishers, the recovering environment also led pers and seahorses. The conch and lobster to higher and more profitable fish catches.

42 habitats habitats 43 Salt Marshes Living Filters along Our Coasts

Remaining European wilderness. Salt marshes are among the only truly natural remaining habitats around the north Sea. one hundred thousand waterfowl overwinter on the north norfolk coast every year. Mark d. Spalding

Filtering and sheltering. The complex array of tidal creeks and salt marshes (here in Georgia, united States) filters pollutants and provides safe

haven for many species. James randklev/Getty images

A smorgasbord for birds data source: TnC and unEp-wCMC 2007. and fish. Salt marshes provide rich feeding SALT MARSH HABITAT. Salt marshes are a major coastal habitat in many low-lying, grounds for wading birds sheltered areas in temperate and northern polar regions. in the tropics, they often mingle (here whimbrels in Virginia, with mangroves, but they can also survive in harsher conditions.

Barry Truitt/TnC united States) and fish.

NORTHERN EuROPE has some of Earth’s the world’s calmest coastlines, behind barrier thrive in desert regions such as the edges of seasonal migrants. Some species, such as stems, and roots also help capture drifting has been allowed back into several former most altered landscapes. Its few remain- islands or in the sheltering arms of estuaries, the Arabian Peninsula, Mexico, and parts of geese, graze directly on the salt marsh plants, sand and silt and hold it together, reducing marshes. Seawalls protecting agricultural ing forest patches have been managed protected from waves that would otherwise northern and western Australia. In contrast while others feast on the numerous inver- erosion and often helping build out new land have been breached, and salt marshes since record keeping began, while the vast, stir the sediments. With each rising tide, with coral reefs, mangroves, and seagrasses, tebrates found in their muddy pastures. land into the sea and lessen the impacts of have returned. The now-regular flow of tides low-lying wetlands of the Netherlands and parts of these marshlands are inundated however, they are most abundant in the Crustaceans and juvenile fish shelter in the storms by buffering waves. Yet like wetlands has deposited new sediments, raising the eastern England were drained several cen- with saltwater that the plants have adapted world’s more temperate realms, and it is in complex maze of channels. all over the world, salt marshes are highly elevation of the newly flooded land. Such turies ago. Even so, you can still see traces to withstand. Then the receding waters drain the North Atlantic region that they are most Humans greatly benefit from this abun- threatened, and vast areas have already been “managed realignment” of coastlines offers of a natural wilderness fringing the edges of into convoluted networks of channels carv- diverse in terms of species. dance, from the wealth of fish, mollusks, damaged by marine pollution or converted a much cheaper alternative to maintaining these lands: dense pastures of grasses, herbs, ing deep into the mud, twisting and turning Coastal salt marshes are among the plan- and invertebrates that we capture in their to agricultural land and urban or industrial sea defenses. It offers a better future for salt and shrubs fringing the sea. These are salt on their way out to sea. et’s most productive natural factories of vicinity. In addition, wetland plants serve development. marshes and for the people who live nearby, marshes: muddy expanses where land plants Salt marshes can be found throughout food for a great web of life. Birds gather in as filters, holding back nutrients and toxic But on the Blackwater Estuary in south- particularly in an era where sea levels are have put down their roots. They occur along the world, from the poles to the tropics. vast numbers as permanent residents or as pollutants that would otherwise enter the ern England, an alternative future is being starting to rise. Able to tolerate dry and saline settings, they ocean from coastal settlements. Their leaves, tested. Here, since the mid-1990s, the sea

44 habitats habitats 45 high Seas and deep oceans Earth’s uncharted “Inner Space” COLD-WATER CORAL REEFS. Less famous than their closely re- lated tropical cousins, cold-water reefs harbor extraordinary communi- ties of life. Most have been found in the north Atlantic, where research has concentrated. The largest, rost reef, cov- ers one hundred square kilometers off the coast of norway. Trawl fishing

is a major and increasing data source: threat to these reefs. unEp-wCMC 2005; Freiwald et al. 2004.

DEEP-OCEAN TRENCHES. Two kilometers deeper than Mount Everest is tall, the Mariana Trench is the data sources: kitchingman and Lai 2004; ramirez-Llodra and Baker 2006. world’s deepest known point. Such exceptionally deep trenches occupy SEAMOuNTS, vENTS, AND SEEPS. By interrupting the less than 1 percent of flow of currents, seamounts receive a rich food supply and the ocean floor, mostly offer safe harbor to plants and animals—many of which are Nourishing flows. in deep in long narrow channels found only at one or a few adjacent seamounts. Large fishing dark waters, far from the life- where one continental vessels have begun to exploit the life seamounts nurture and giving rays of the sun, the rich plate is being subducted are destroying these isolated communities. on the seafloor, mineral nutrients of vents and under another. They are superheated and mineral-rich waters of hydrothermal vents seeps nourish great densities exotic worlds dominated and the methane and sulfide-rich waters that leak out as cold of bacteria. These in turn feed by sea cucumbers, seeps support life as well. expansive colonies of clams, mollusks, crustaceans, worms, and mussels. data source: Based on nGdC and ESri 2004. and worms. dr. Bob Embley, noAA pMEL Bob Embley, dr.

OF ALL OF EARTH’S HABITATS, the largest is seas—the pelagic ocean—and the seabed and even giant squid, as well as large ocean- tuna are being overexploited, and many the ocean’s muddy depths, primarily concen- collaboration to protect their biodiversity. liquid—the vast open space of the oceans before they are irrevocably changed. roving seabirds such as the albatross. shark species are threatened with extinction. trated on the undersea mountains known as At this writing, there was not a single pro- and seas. Oceans cover two-thirds of the Staying still is never an option in the open Scientists continue to identify new ocean Spreading over twice the area of all the seamounts and in the communities around tected area in all their expanse. But there have planet, yet they remain mostly foreign to sea. Throughout its depths, hunters and species. A few smaller whales are known from continents combined, the deep seabed is hot volcanic vents and cold seeps. been some victories. A 1986 moratorium humanity. Many more people have jour- hunted play their parts in constant motion, just a handful of sightings or from skulls dark, cold, and crushed by immense water Reports of the declining state of the oceans on commercial whaling saved a number of neyed to outer space than have visited even shifting with the winds and currents. At the washed onto remote shores. But even as spe- pressure. Until the late nineteenth century, have prompted efforts to manage them bet- whale species from extinction, while bans by the average depths of the world’s oceans, a bottom of the food chain are microscopic cies are still being discovered, they are facing scientists assumed these conditions could not ter. There are regulations controlling fishing several nations in the early 1990s curbed the distance of some 3,800 meters. algae and phytoplankton, which convert mounting dangers from human develop- possibly sustain life. But then small samples in deep waters adjacent to many countries, use of large-scale drift nets in the high seas. Facing recent evidence suggesting that solar energy to sugars and nutrients, the ment. Fishing vessels have scoured the high of the seabed were hauled up, containing but the “high seas,” outside any national The nets—dubbed “walls of death” by some some 40 percent of oceans have been strongly stuff of life. They in turn provide meals for seas for centuries, first targeting the great previously unknown sea cucumbers, worms, jurisdiction, are by nature a much greater environmentalists—were up to fifty kilome- affected by human activities, scientists have plankton, such as crustaceans and jellyfish, whales, but now tuna, billfish, sharks, and and crustaceans. Modern evidence has re- challenge. Making up half the total area of ters long. Aimed at tuna and billfish, they joined in a race to understand the open which subsequently feed ocean-faring hunt- even tiny krill. Whale stocks have collapsed, vealed there could be as many as ten million Earth, it will take concerted international caught everything in their path, including ers, including tuna, billfish, sharks, whales, still-unidentified types of animals living in dolphins, turtles, and seabirds.

46 habitats habitats 47